Relaxation dynamics in borate glass formers probed by photon correlation at the microscopic and macroscopic length scale

X-ray photon correlation is used to probe the dynamics of the strong glass former boron trioxide and of a series of alkali borate glasses, (M2O)x(B2O3)1-x where M is the alkali modifier (M=Li, Na and K). The decay times τ of the obtained correlation functions in B2O3 are consistent with visible light scattering results and independent of the incoming beam intensity in the undercooled liquid phase; are instead temperature independent and show a definite dependence on the X-ray beam intensity in the glass. We are therefore witnessing an atomic dynamics induced by the X-ray beam. Furthermore, we clearly demonstrate that the value of τ is related to absorption by investigating a series of alkali borate glass with the same molar ratio and as a function of the alkali modifier. Finally, we highlight the role played by the structure in the X-ray induced dynamics by studying a series of lithium borate glasses with different molar ratios, and by investigating the wave vector dependence. Despite the observed dynamics is clearly intensity dependent, we obtain very interesting information on glasses not available with other experimental techniques.

Grantor dc:publisher

Università degli studi di Trento

Year dc:date

2017

Author dc:creator

• Pintori, Giovanna

Contributors dc:contributor

• Monaco, Giulio

• Settore FIS/01 - Fisica Sperimentale

Statement dc:rights

• info:eu-repo/semantics/openAccess
• license:Tutti i diritti riservati (All rights reserved)
• license uri:iris.PRI01

Language dc:language

eng

Identifier

http://dx.doi.org/10.15168/11572_368421
10.15168/11572_368421

OAI identifier oai:identifier

oai:iris.unitn.it:11572/368421